From 0ee7a39594ac2f8a237e4c0fb1c3296d49c6788a Mon Sep 17 00:00:00 2001 From: goldsimon Date: Tue, 30 Jan 2018 22:01:54 +0100 Subject: [PATCH] tcp: add comments about usage of options --- src/include/lwip/priv/tcp_priv.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/src/include/lwip/priv/tcp_priv.h b/src/include/lwip/priv/tcp_priv.h index 9987657a..baa54122 100644 --- a/src/include/lwip/priv/tcp_priv.h +++ b/src/include/lwip/priv/tcp_priv.h @@ -261,12 +261,12 @@ struct tcp_seg { u8_t chksum_swapped; #endif /* TCP_CHECKSUM_ON_COPY */ u8_t flags; -#define TF_SEG_OPTS_MSS (u8_t)0x01U /* Include MSS option. */ +#define TF_SEG_OPTS_MSS (u8_t)0x01U /* Include MSS option (only used in SYN segments) */ #define TF_SEG_OPTS_TS (u8_t)0x02U /* Include timestamp option. */ #define TF_SEG_DATA_CHECKSUMMED (u8_t)0x04U /* ALL data (not the header) is checksummed into 'chksum' */ -#define TF_SEG_OPTS_WND_SCALE (u8_t)0x08U /* Include WND SCALE option */ -#define TF_SEG_OPTS_SACK_PERM (u8_t)0x10U /* Include SACK Permitted option */ +#define TF_SEG_OPTS_WND_SCALE (u8_t)0x08U /* Include WND SCALE option (only used in SYN segments) */ +#define TF_SEG_OPTS_SACK_PERM (u8_t)0x10U /* Include SACK Permitted option (only used in SYN segments) */ struct tcp_hdr *tcphdr; /* the TCP header */ };